The Influence of Skull Thickness on Intracranial Biomechanical Response / 医用生物力学

Objective To study the influence of skull thickness on intracranial biomechanical parameters by finite element method. Methods The female head at 5th percentile was selected for CT scanning to construct finite element model of the head with high biofidelity,and the model was verified by reconstructed cadaver test. The finite element model of the head with different skull thickness was established, and multiple groups of tests were carried out to compare the intracranial mechanical parameters. Results The negative value of intracranial pressure was significantly affected by the decrease in skull thickness under the same head size, while the negative value of intracranial pressure was slightly affected, with an increasing trend. The shear stress and von Mises stress of brain tissues were significantly increased with skull thickness increasing. Conclusions Under the same head size, the skull thickness will affect head injury to a certain extent, and people with small skull thickness are more likely to be injured than those with large skull thickness.

Effect of N-acetyl-L-cysteine on bioavailability and brain distribution of curcumin by nasal delivery / 中国中药杂志

Curcumin( Cur) is a natural active substance extracted from the roots or tubers of traditional Chinese medicinal materials. It has anti-inflammatory and anti-tumor activities on brain diseases. Due to the poor stability,low solubility,poor absorption and low bioavailability of curcumin,N-acetyl-L-cysteine( NAC) was used as an absorption enhancer and mixed with curcumin to improve the absorption of curcumin in the body. In this paper,curcumin was smashed by airflow pulverization,and Cur-NAC mixtures were prepared by being grinded with liquid. Then,the raw material and the product were analyzed by differential scanning calorimetry( DSC),X-ray diffraction( XRD) for structural characterization. The dissolution was determined by high performance liquid chromatography( HPLC) analysis. The characteristic peaks of the samples prepared by grinding method were similar to those of the raw materials,while the melting temperature and the accumulated dissolution degree were not significantly changed. The crystal forms of the products were not changed,and no new crystal form was formed after grinding. After the administration of intranasal powder,blood samples were collected from the orbit,while the whole brain tissues were removed from the skull and dissected into 10 anatomical regions. The concentrations of curcumin in these samples were determined by UPLC-MS/MS. The concentrations of curcumin in plasma and brain were compared at different time points. After intranasal administration of two drugs,it was found that the concentration of curcumin after sniffing up the mixtures in plasma was high,and the concentration of the drug in the olfactory bulb,hippocampus,and pons was increased significantly. Within 0. 083-0. 5 h,the olfactory bulb,piriform lobe and hippocampus remained high concentrations,the endodermis,striatum,hypothalamus and midbrain reached high concentrations within 1-3 h; and the cerebellum,pons and brain extension maintained relatively high concentrations within 3-7 h. The experiment showed that nasal administration of Cur-NAC mixtures can significantly improve the bioavailability of curcumin,and lead to significant differences in brain tissue distribution.

Research progress of CYP450 genes expressed in brain involved in the metabolism of endogenous substances / 中国比较医学杂志

Cytochrome P450 (CYP450) is a superfamily of heme-thiolate proteins, which is involved in the metabolism and activation of various endogenous and exogenous substances, including food, drugs and pollutants. Previous studies of the CYP450 genes mainly focused on their function in drug metabolism. However, in recent years, studies have found that CYP450 are also involved in the development and progression of various diseases, including Parkinson's disease (PD), cancer, cardiomyopathy and heart failure (HF). By far, the process and related mechanisms of CYP450 in the metabolism of endogenous substances in brain tissues has not been clarified yet. In this paper, we summarized the research progress of CYP450 genes involved in the metabolism of endogenous substances, in order to provide a new idea for the exploration of the functions of CYP450 genes expressed in the brain.

Pathological changes of brain tissues from contused and contralateral non-contused sides and their significance / 中华创伤杂志

Objective To investigate the pathological changes of brain tissues from contused and contralateral non-contused sides and their significance.Methods A total of 100 healthy adult Wistar rats were assigned to brain contusion group and sham operation group according to the random number table.Ten rats in each group were sacrificed at 1,3,6,12,and 24 hours respectively.Brain samples were collected to perform pathophysiological analysis of brain tissues and test blood brain barrier (BBB)permeability by semiquantitative immunohistochemical staining of IgG.Results There was no damage to the bilateral brain tissues in sham operation group and IgG stain was negative.In brain contusion group,angioedema characterized by the breakdown of BBB was seen in the contused side at 1 hour followed by cellular edema at 3 hours,with aggravation of both over time.Moreover,tissue necrosis,inflammatory cell infiltration,and microglia proliferation emerged at 12 hours.Besides,IgG-positive staining was seen at 1 hour,was strongest at 6 hours,and remained a high level at 24 hours.With respect to the non-injured side in brain contusion group,no pathological abnormalities and negatively stained IgG were observed at 1 hour; cellular edema and weakly positive-stained IgG were found at 3 hours; aggravated cellular edema,emergence of angioedema,and IgG strongly positive staining were noted at 6 hours;cellular edema continued aggravation,but angioedema tended to be attenuated,IgG staining weakened,and microglia proliferation were observed at 12-24 hours.Conclusion Pathological changes of brain tissues from the contused and contralateral non-contused sides are differed,which provides a basis in determining treatment choices.

Standard decompressive craniectomy with large bone flap resection and removal of necrotic brain tissues for malignant brain swelling after brain injury / 中国综合临床

Objective To observe the curative effects of malignant brain swelling after brain injury by using the operations of standard large Craniotomy decompression and removal of necrotic brain tissues. Methods 80 cases of malignant brain swelling after severe brain injury were observed. The standard decompression surgery of large era-niotomy routine were used in 40 cases,while the operations of standard large craniotomy decompression and removal of necrotic brain tissues were used in the other 40 cases. The curative effects of the results after 15 days and six mon-ths were analyzed. Results The incidence of intracranial hypertension (37.5%, 15/40 ) and brain tissue incisional hernia (32.5% ,13/40)of the group using standard large craniotomy decompression and removal of nee-rotic brain tissues treatment was significantly lower than that of simple standard large craniotomy decompression treat-ment group [15.0% (6/40) vs 10.0% (4/40)] after 15 days (P<0.05 ). The prognosis excellent rate ( good + re-sidual) of the group using standard large Craniotomy decompression and removal of necrotic brain tissues treatment was significantly higher (60.0%) than that of simple standard large craniotomy decompression treatment group (40.0%) after six months (P<0.05 ). Conclusion The operations of standard large craniotomy decompression and removal of necrotic brain tissues can effectively reduce the intracranial hypertension of malignant brain swelling after trauma injury,and reduce mortality and morbidity of severe brain injury.

The expressions of IGF-1 in HIE neonatal rabbits / 重庆医科大学学报

Objective:Searching after the regularity of the expressions the insulin-like growth factors(IGF-1) inside the neonatal rabbits with chronic intrauterine anoxemia give to brain Tissues and serums. Methods: Choosing 24 Zelanian rabbits that have been in afternoon pregnancy,we divide them into three stochastic contratest group by chance: the control group,the anoxic group and the group interfered with Chinese traditional medicine. Then we contrast the expressions and changes of these groups with IGF-1 in brain tissues and in serums. Results: Contrasting IGF-1 in brain tissues,checked up with ?2. In three different groups,we have found that the differences of their expressions have some statistical significance (P

Relationship between nitric oxide and superoxide dismutase in different brain tissues in delayed neuronal death rats / 吉林大学学报(医学版)

0. 05). When reperfusion time was prolonged, the level of NO in the experiment group was decreased gradually and was lower than that in control group (P

Change of Gq protein-phosphatidyl inositol signaling in brain of rats with acute respiratory distress syndrome / 中国病理生理杂志

AIM: To study the change of Gq protein-phosphatidyl inositol signaling in the brain of rats with acute respiratory distress syndrome(ARDS).METHODS: Forty male Wistar rats were randomly divided into oleic acid groups(OA groups of 30 min,60 min,90 min and 120 min exposure) and control group.The ARDS model in rats was reproduced by intravenous injection of oleic acid(0.2 mL/kg in 2 min).The mean arterial blood pressure(MABP),blood gas indexes,malondialdehyde(MDA),lactate dehydrogenase(LDH) and creatine kinase(CK) in plasma and brain tissues were measured.G?q/11 protein and phospholipase C in brain tissues were detected by Western blotting.RESULTS: Compared to control group,MABP and PaO2 in all OA groups obviously decreased(P